Telephony.



No. 781,888. PATENTED FEB. 7, 1905. I. KITSEE.

TELEPHONY.

APPLIOATION FILED APR. 4. 1901.

U llmlllhli a Q "Q 9 Q 4 r ssasf' i z Patented February 7, 1905..

PATENT @FFTCE.

ISIDOR KITSEE, OF PHILADELPHIA, PENNSYLVANIA.

TELEPHONY.

SPECIFICATION forming part of Letters Patent No. 781,888, dated February'7, 1905.

Application filed April 4, 1901. Serial No. 54,308.

Be it known that I, Isroou Krrsnn, of the city and county ofPhiladelphia, State of Pennsylvania, have invented certain new anduseful Improvements in Telephony, of which the following is aspecification.

My invention relates to an improvement in telephony, and has morespecial reference to the method of and arrangement for connecting twosubscribers stations at the central or exchange for the purpose ofintercommunication.

It is well known by persons versed in the art that to connect twosubscribers stations according to the practice of to-day the subscriberscircuits are disconnected from the socalled common battery and areconnected through a cord with each other and with a second source ofcurrent and that at least four operations are necessary before twosubscribers are disconnected and connected again.

It is the aim of my invention to facilitate the work at the central.

Referring to the drawings, Figure l is a diagrammatic view of atelephone system, showing three subscribers stations and a centralstation, subscriber No. 1 and No. 2 being connected so as to communiaitewith each other. Fig. 2 is a sectional view of one of the plugs.

A A are the subscriber-lines of the dift'erent stations No. 1', No. 2,and No. 3. These stations are illustrated in conventional signs; but itis understood that other devices may be placed in these stations, and,intact, as my invention does not relate to the same, I thought itunnecessary to give in detail the devices usually placed at outlyingtelephonic stations.

B a common return for the three stations. I have illustrated here thissystem as consisting for each subscriber of one line-wire connected toone common return; but it is obvious that a metallic circuit may besubstituted without departing from the scope of my in vention.

At the central, (7 is the common battery; I). D and I), the wiresconnecting one pole of the battery to one spring-jack of the threecircuits, respectively. (I (1 are the spring-jacks.

F and (Lt are the two coils of an inductorium.

The terminal of the coil F terminates in the cord I and the terminal ofthe coil G terminates in the cord (wr'. The ends of the cord I1 areconnected to the plug E, which plug consists of the conducting parts 1'and w, insulated from each other by the insulating material f. The endsof the cord G are connectcd to the plug II', which plug consists of theconducting parts and w, insulated from each other by the insulatingmaterialf". Both plugs are in construction alike.

Each operator is provided with a series of imluctoriums, the primariesas well as the secondaries of which are preferably wound in like manner-that is, the resistance and in ductive capacity of one coil shouldequal the resistance and inductive capacity of the other coil. Thesecoils preferably are, as usual, provided with a soft-iron core. Theterminals of each of these coils are connected to a cord, which cordterminates in a plug. These plugs are so arranged that an operator, itcalled upon to connect two subscribers stations, has to insert one ofthese plugs in the circuit calling and the other of these plugs in thecircuit to be called.

Normally the spring-jacks 1/ and d are in contact with each other, andthe lines are thereby in electrical contact with the battery U. .It' nowa subscriber wishes to be connected with a second subscriber for thepurpose of iutercommunication, the operator places one plug of one pairof cords between the spring-jacks ot the circuit calling and the secondplug of the same pair of cords between the spring-jacks ot' the circuitof the subscriber to be called. 'llhrough this operation one coil isplaced in series with the calling'circuit and the second coil is placedin series with the circuit to be called. Supposing subscriber No. 1calls for subscriber No. 2, one plug is inserted between spring-jacks ofA and the second plug is inserted between the spring-jacks of A". Itsubscriber No. l talks to subscriber No. 2, then the varying currentflowing through coil F will induce impulses in coil (t, and theseimpulses will be received by the subscriber No. 2, and it' subscriberNo. 2 answers subscriber No. 1 then the varying impulses flowing throughcoil G will induce impulses in coil F and the same will be received withthe aid of the receiver by subscriber No. 1.

It is preferred to make the plug of such construction that the operatorhas always to place the same in a position so that one of its conductingparts shall be in contact with the upper part of the spring-jack and theother of its conducting parts shall be in contact with the lower part,if inserted between the same.

I have not shown in the drawings any of the indicating devices, such aslamps, &c., or any of the calling-up or ringing-up devices. I also havenot shown the switchboard or operators phone, as the functions of thesedevices are well understood and do not form part of my invention. Thesedevices may be placed between the breaks in the circuit. Ihave alsogiven only conventional signs for the subscribers stations, as thearrangement of the same is not part of my invention. I purposely abstainfrom illustrating in detail the devices and arrangements of same placedat the subscribers stations, or the necessary parts, signal devices,&c., as placed to-dayat the centralstation, for the reason that myinvention is applicable to any of the systems used to-day.

The main feature of my invention is the introd uction of an inductoriumbetween two subscribers lines for the purpose of intercommunication,such inductorium not being normally in the line, and after communicationhas ceased'the inductorium is again disconnected from said lines. Withthis device it is not necessary to cut off the lines from thecalling-battery and connecting the same to another socalledspeaking-battery. To persons versed in the art the underlying principlewill be readily understood, and in my experiments, repeatedly made,Ihave always found that, for the purpose of intercommunication betweentwo lines, the introduction of the cord-coil,

such as described, results in far better receiving the speech than whenthe coil was omitted from the cord and both lines connected in series asto each other. This arrangement has also the great advantage that thetwo lines are left in multiple, and the resistance, therefore, is farless than if placed in series, as is the case to-day. On an average, itmay be stated, that the resistance is nearly half, taking intoconsideration that the length of the lines differ. As to the number ofoperations to connect two lines, this arrangement necessitates less thanhalf the operations now required.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

In a telephonic system wherein two or more outlying or subscribercircuits center in one exchange, acommon battery in said exchange,movable means for one terminal of each of said circuits, a series ofmovable means connected to one terminal of the battery-circuit, themovable means of the outlying circuits connected each electrically toone of the series of said movable battery means, means to connect two ofthe outlying circuits with each other, said connecting means consistingof two plugs, an electric circuit for each of said plugs, a coil foreach of said circuits, the coils of both circuits in inductive relationwith each other, each of the plugs embracing two conducting partsinsulated from each other, each of the conducting parts in electricalcontact with one terminal of its own circuit.

In testimony whereof I hereby sign my name, in the presence of twosubscribing witnesses, this 22d day of March, A. D. 1901.

ISIDOR KITSEE.

Witnesses:

EDITH R. STILLEY, CHAS. KREssnNBUcH.

